Effect of glucose and reducing agents on syngas fermentation by clostridia species P11

Scope and Method of Study. The purpose of this study was to determine the effect of glucose and reducing agents on syngas fermentation using P11. The first objective of the study is the effect of glucose, this study was conducted to overcome the lag period and to increase cell concentration to increase ethanol yield. Second objective of the study is the effect of various reducing agents such as methyl viologen, benzyl viologen and neutral red on fermentation using P11. This study was based on the hypothesis that these reducing agents are capable of altering the metabolism towards solventogenesis by disrupting the NADH/NAD ratio.;Findings and Conclusion. The glucose study shows that the initial growth of cells on glucose helps to reduce the lag period and to increase the cell concentration. However, the use of glucose to grow an inoculum for syngas fermentation did not increase the maximum ethanol concentration produced when compared to using syngas to grow inoculum.;The study with reducing agents shows that the addition of 0.1mM of methyl viologen produced maximum ethanol concentration of 1.3g/l while neutral red produced 0.6g/l of ethanol and control produced 0.5g/l of ethanol.0.1mM of benzyl viologen did not have any produce ethanol. Furthermore, methyl viologen also decreased the amount of acetic acid produced. Optimum concentrations of reducing agents are required to up regulate the solventogenesis in P11.